Indeed, that is the speedbrake. A handle on the pedestal is used to
select the speedbrake anywhere between 0 and 60 degrees (to either
side). The control system will set the speedbrake to an angle
corresponding to the selection made below 190 kts. Above 190 kts, the
speedbrake will deploy partially, providing a constant decelleration of
0.1 G down to 190 kts. Also, when either power lever is moved forward
to, or over the detent (a go-around situation) the speedbrake will
automatically close.
Regards,
Erik Verheijden.